This invention relates to an energy recovery system wherein refrigerating apparatus is utilized to heat water for use as auxiliary hot water in a water system. More particularly, the invention provides for cooling the heat generating components of refrigerating apparatus and recover some of the energy used in operating the components in the form of by-product heat for heating water to provide auxiliary hot water to a water system.
In a typical refrigeration circuit, such as utilized in household refrigerators, considerable heat is generated during the compression of the system refrigerant, and such heat occurs in the hot gases being compressed. The possibility of utilizing this waste or by-product heat has long been recognized and the prior art discloses a number of arrangements wherein this heat can be recovered for practical use, usually for water heating purposes, and reference may be made to U.S. Pat. Nos. 2,042,812; 2,125,842; 2,700,279; 3,301,002; and 4,141,222.
In refrigerating apparatus, the condenser acts to cool the high temperature refrigerant gas delivered to it from the compressor in order to convert the gas into liquid. It is desirable to be able to cool the condenser as by a water cooling arrangement thereby enhancing its functional purpose in the refrigerating system and also recover the energy expanded in producing the by-product heat by using the water heated in the process of cooling the condenser as auxiliary hot water in a water system. With such a water cooling arrangement, it is desirable that minimum heat be expelled to ambient. Also, the customary fan used to cool the components may be eliminated.
Several types of controls have been utilized to prevent excessive water temperatures from occurring within the hot water storage tank in energy recovery systems used in conjunction with refrigerating apparatus. One such system is disclosed in U.S. Pat. No. 2,042,812 wherein a pump which circulates water from the hot water storage tank through the refrigerating apparatus and back into the tank operates only when the hot water in the tank is below a maximum preselected temperature. Such an arrangement causes the circulating pump to continually cycle, and during continuous refrigeration system operation during low hot water consumption periods, the water within the storage tank may be subject to stratification thereby limiting the water temperature level within the tank. Moreover, the lack of water circulation in the refrigerating apparatus system during its operation does not provide for cooling of the operating components such as the condenser and compressor. In addition, the by-product heat generated during the time the refrigerating apparatus is operating is not recovered and utilized for heating water.
Other energy recovery systems utilize a separate heat exchanger in conjunction with the refrigerating apparatus and have water from a tank conducted through the heat exchanger or not through the heat exchanger depending upon a predetermined water temperature being achieved. See, for example, U.S. Pat. No. 4,141,222. Such a system, however, does not provide for cooling of the heat generating components of the refrigerating apparatus in the event that the water in the tank is hot enough so that the heat exchanger is bypassed.
By my invention, there is provided in a hot water system a means to obtain auxiliary hot water by recovering heat generated by refrigerating apparatus and at the same time provide a cooling system for the refrigerating apparatus which allows for more efficient operation of the refrigerating apparatus.